Gas-cell construction



March 17, 1931. A, M S 1,797,189

GAS CELL CONSTRUCTION Filed Jan. 27, 1950 gwuwntoz Arum r DCwmn/mq s Patented Mar. '17, 1931 "UNITED STATES.

PATENT; OFFICE ARTHUR'DONALD GUMMINGS, or PORTLAND, MAINE, ASSIGNOR 'ro 'rHE GOODYEAR TIRE & RuBBEn'comPANY, or AKRON, OHIO, A CORPORATION or OHIO GAS-CELL CONSTRUCTION Original application filed March 8, 1928, Serial No. 260,252. Divided and this application filed January 27, 1930. Serial No. 423,894.

This invention relates to coated fabrics and "it has particular relation to fabrics that are coated with gold beaters skin, cellulose'derivatives, or other films adapted to render the fabric impermeable to hydrogen, helium and similar highly bouyant'gases.

This application is a division of application Serial No. 260,252, filed March 8, 1928.

One object of the invention is to provide a l coated fabric such as is used in the construction of gas containers for balloons, that has an exceptionally high degree of flexibility.

Another object of the invention is to provide certain novel methods of manufacturing fabrics of the above designated character.

Heretofore, the gas containers for lighter than-air craft have been constructed of fabrics, such as closely woven'cotton, silk or linen. These fabrics were coated with a highly impermeable film or coating that, in some cases, was applied in the form of a sheet which was cemented to the-fabric by means of a suitable adhesive, such as glue or gelatin. In other cases, the coating film was applied in the form of a solution or cement which was either precipitated upon, or allowed to dry upon, thefabric. In either case, the coated fabrics were relatively stiff and the fllms frequently cracked when subjected to repeated 0 or sharp flexure.

the coating permitted the escape of the highly fluid inflating gases.

This invention consists in the discovery that the excessive stiffness of the fabrics was caused by the fact that a certain amount of the adhesive was absorbed into the fabric which acted as a filler and thereby materially decreased the flexibility of the. fabric. It has been discovered that by impregnating the fabric with ,a re-agent that reduces the wetting power of the cement and consequently the absorption thereof by the fabric, the flexibility of boththe fabric and the coating is materially enhanced.

For a better understanding of the invention, reference may now be had to the accompanying drawings, forming a part of the specification, of which:

Fig. 1 is a fragmentary View of a portion of a gas cell for lighter-than-air craft; an Fig. 2 is a cross-sectional form of fabric.

In practicing the invention, a gas cell 10 is formed by impregnating a sheet of fabric 12 with a suitable material and by coating the fabric with a layer 14: of glue, gelatine or other suitable substance which acts as an adhesive for a gas impervious layer 16 applied thereto.

The character of the impregnating ingredients for the fabric 12 varies for different cements, but, if the fabric is coated with gold vbeaters skin or sheets of precipitated cellulose, it has been found that aluminum acetate may be employed with excellent results. The latter compound may be conveniently prepared by intermixing two solutions, one con sisting of 35 grams of crystallizedaluminum sulfate, dissolved in 500 cc. of water, and the other consisting of 75 grams of lead acetate, also dissolved in 500 cc. of the same solvent. Thelead sulfate formed is precipitated in the form of a sludge and the clear supernatant liquid containing the aluminum acetate may The cracks thus formed in be decanted oil".

The fabric to be treated is'then dipped in or sprayed with the liquid and is allowed to dry. After drying, the fabric may be coated with the layerl l of an aqueous solution of glue or gelatin to which the layer 16 of gold beaters skin or a sheet of cellulose derivative, such as the product known commercially as cellophane, is applied. As shown in Fig. 2, a sheet .of fabric 20 may, also, be coated directly "with a layer 22 of gelatin or cellulose xanthate precipitated in situ upon the fabric. In either case the method of proview of ano her cedure is substantially the same as that ordi- The invention is not limited to the employment of aluminum acetate as an impregnating reagent, but aluminum oleates and stearates may also be employed with excellent results. Since the latter are insoluble in water, it is necessary to form them directly in the fibers of the fabric which may be conveniently accomplished by wetting the fabrics with an aqueous solution of sodium or potassium stearate or oleate and then wetting with a soluble aluminum salt, such as aluminum sulfate. The corresponding aluminum oleate or stearate is then, precipitated as a thin coating upon the individual fibers of .which the fabric is composed.

The flexibility of fabrics may also be increased by impregnating them with calcium oleates or stearates prior to the application of the impermeable film. Calcium oleates and stearates like the corresponding aluminum salts, are insoluble in aqueous solutions. It is, therefore, necessary to employ a method of impregnation similar to that employed in connection with the corresponding salts; for

example, the fabric may be impregnated with a potassium or sodium oleate or stearate and then steeped in a solution of calcium acetate. In this case, each individual fiber is coated with a thin film of an insoluble calcium soap which serves ,to reduce greatly the surface tension between the fibers and the water contained in the cement which is in contact zvith the surface of the fabric.

The employment of any of the reagents described as an impregnating material renders the fabric highly impermeable to water and moisture. There is, therefore, much less danger of the coating film becoming loosened from the fabric due to the absorption of moisture by the latter.

Although I have described in detail only the preferred embodiments of theinvention, it will be apparent to those skilled in the'art that it is not so limited but that various minor modifications may be made therein without departing from the spirit of the invention or from the scope of the appended. claims.

What Iclaim is:

1. A gas cell for lighter-than-air craft composed of fabric comprising a textile base impre nated with an open chain or anic acid salt of aluminum capable of ren ering the textile material highly impermeable to the absorption of moisture and having a coating of gas resistant material cemented to the surface of said textile base 7 by means of a gelatin containing cement.

.2. A gas cell for lighter-than-air craft composed of fabric comprising a textile base impregnated with a waterproofing material, a coating of an agglutinant upon the textile material, and a ply of material highly impermeable to inflating gases disposed upon the agglutinant.

3. A gas cell for lighter-than-air craft com- 

